Objective The aim of this study was to determine the appropriateness of messages on osteoporosis in Spanish videos posted on YouTube. Methods YouTube Spanish language videos on osteoporosis were evaluated. The main variable was the presence of appropriate messages related to osteoporosis. The content was evaluated through a checklist based on available guidelines and reviewed by an expert (E.C.L.). The evaluation was performed twice independently for each video. A discussion of discordant messages was made with the expert. Other variables included were number of views, comments, “likes,” and “dislikes”; the total duration of the video; and their source (health professionals and non–health professionals). Bivariate analysis between health professionals and non–health professionals were performed using the Mann-Whitney U and the χ2 tests. Results A total of 148 videos were reviewed. The median appropriate score for all videos was 5 (p25: 3, p75: 9) (maximum possible, 29 points). Seventy-three (49%) videos had a health professional as source, 124 (83.8%) mentioned at least one message in the definition area, 99 (66.9%) in the area of diagnosis, 99 (66.9%) in the area of recommendations, 43 (29.1%) in the area of treatment, and 5 (3.4%) in follow-up. The most frequent message was “risk of fracture” (68.9%). Conclusions The content of osteoporosis information found in YouTube was generally incomplete and inaccurate. The content of these videos should include treatment and preventive strategies.